Polymerizable liquid crystal used for fabricating optically anisotropic film has suffered from that it often crystallizes in the process of coating or after dried.
As a countermeasure, it has been known that mixing of a target polymerizable liquid crystal with other polymerizable liquid crystal successfully suppressed the crystallization. Known examples of suppressing the crystallization include use of a composition which contains a (meth)acrylate compound having two (meth)acryloyl groups on the molecular terminal together with the other polymerizable liquid crystal compound; and use of a composition prepared, in the process of manufacture, as a random mixture of polymerizable liquid crystals having a (meth)acryloyl group and an alkyl group on both molecular terminals. The method, however, showed only limited degrees of suppressive effect on crystallization.
As a method for manufacturing a liquid crystal composition containing two or more species of polymerizable liquid crystals, there have been reported methods for manufacturing a liquid crystal composition containing two or more species of polymerizable liquid crystals all at once, using two or more species of raw materials. For example, Patent Literature 1 describes a method for synthesizing a liquid crystal mixture containing two or more species of polymerizable liquid crystals, using a compound having a hydroxy group or derivative of the a compound having a hydroxy group, and a nucleophilic compound having a non-carboxyl-type leaving group and a polymerizable group. The method is reportedly successful in manufacturing the liquid crystal composition with a high liquid crystallinity, in a time-saving and cost-saving manner. Patent Literature 2 describes a method for manufacturing a composition containing two or more species of polymerizable liquid crystals, by allowing a compound having hydroxy group and so forth, to react with a compound having a carboxyl group derivative and a polymerizable group.